Operator s keyboard apparatus and circuit therefor



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o e C. E. SGRIBNBR 8.-, F. R. MGBBRTY. @PERATORS KEYBOARD APPARATUS ANDGIRGUIT THPREPOR.-

N6. 664,466. Patented July 21, 1896.

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UNITED STATES PATENT OFFICE,

CHARLES E. SCRIBNER, OF CHICAGO, AND FRANK RIVICBERTY, OF DOWNERS GROVE,ILLINOIS, ASSIGNORS TO THE WESTERN ELECTRIC COMPANY, OF

CHICAGO, ILLINOIS.

OPERATORS KEYBOARD APPARATUS AND CIRCUIT THEREFOR.

SPECIFICATION forming part of Letters Patent No. 564,456, dated July 21,1896.

Application filed September 28, 1893. Serial No. 486,730. (No model.)

ing drawings, forming a part of this specification.

Our invention relates to mechanism of telephone-switchboards, moreparticularly to the keys or switching mechanism and circuit connectionsappropriate thereto furnished the operator for connecting her telephonewith' the plug-circuit and for calling subscribers, its objects being toreduce the number of manipulations of keys required :in makingconnection between subscribers and to construct a compact and easilyaccessible form of key. Hitherto it has been common to provide eachoperator with a number of keys, each controlling the connection of hertelephone with a single plug-circuit, and another independent set ofkeys for calling a subscriber after connection was made with his line,these different keys being independently manipulated, and thus requiringa number of distinct operations in completing connection betweensubscribers. VThese keys have been commonly arranged upon the under sideof a shelf or keyboard upon the front of the switchboard, the springs ofthe keys projecting downward and being with difficulty reached forinspection or adjustment.

Our invention herein relates to a combination listening and ringing keyconstructed to be operated by three buttons, the mechanism and circuitsthereof being so arranged that the depression of one button connectstheoperators telephone with the plug-circuit, the depression of anotherbutton disconnects the operators telephone and connects in place thereofa clearing-out annunciator of usual construction, while the operation ofthe third button alone disconnects the operators tele- 5o phone.

key.

Each plug-circuit, or. pair of connectingplugs, is equipped with onesuch combination- In practice the operator leaves her keys in positionto connect her telephone with all of the pairs of plugs which are outofuse, so 55 that upon inserting any plug into a subscribers.spring-jack she is in position to communicate with the subscriber ofthat line, the clearing-out annunciators being in that position ,of thekeys disconnected from their re- 6o spective pl ug-circuits, so as toavoid their shunting telephonic current. Having completed theconnection, the operator depresses the last-mentioned key, thus sendinga calling-signal to the subscriber called for, and at the same timeautomatically disconnecting her telephone from the plug-circuit employedand substituting for the telephone a clearing-out annunciator. Anadditional function of the key, when self-restoring clearing-out 7oannunciators are employed, is to restore or reset this annunciator byclosing a local circuit through its restoring-magnet, this being4`accomplished by means of contact -points which are brought intooperation when the telephone is connectedwith the plug-circuit. Thecalling-key is arranged to open one side or conductor of theplug-circuit to prevent the calling-current from finding circuit back tothe subscriber who initiated the connec- 8o tion. A single independentkey is provided in the branch including the operators telephone,connected with the source of signaling-current, by which the operatormay close this source of signaling-current to the circuit in a manner toring out to the substation of the call-initiating subscriber.

Our improved key is constructed with its various contact-springs andanvils arranged in the same plane, parallel with the base upon 9o whichthe key is mounted, sow that when in place upon the keyboard the latter,which is hinged at one edge, may be turned over, disclosing all thecontact points and surfaces and the entire mechanism of the key, so thatthe circuits may be readily traced and the switch-contacts inspected oradjusted. The

p springs are arranged at only a slight elevation y Yfrom Vthe base ofthe key, so asto occupy a very small space beneath the keyboard, thusroo permitting the close approach ofthe operator to the switchboard, adisadvantage of the former keys, occupying a larger space beneath thekeyboard, being that they necessitated the elevation of the keyboard topermit the operators to sit at the board, thus encroaching upon thespace assigned to the springjacks upon the switchboard.

Our invention is illustrated in the accompanying drawings and may bedescribed in greater detail in connection therewith.

Of the drawings, Figure l is a side elevation of a form of ourcombination-key. Fig. 2 is a plan thereof from beneath. Fig. 3 is acentral longitudinal section of the key, the latter being shown mountedupon a hinged keyboard, as described. Fig. 4 is a diagrammaticrepresentation of an arrangement of circuits appropriate to our improvedkey.

The key comprises, essentially, a base-plate a, to which is pivoted,near its center, a lever b. Upon this lever the stems of threepushbuttons c, cl, and e bear, the buttons being adapted to niovevertically in tubular projections a a2 a3, respectively, of thebaseplate, and being limited in their downward motion by shoulders cutupon the stems. Opposite its pivot the lever b carries anirregular-shaped block or wedge b', of insulating material, at theextremity of a short stem. This block is adapted to move nearlyhorizontally between the extremities of a set of switeh-sprin gsarranged upon each side of it, secured at their distant extremities inblocks b3 b3, of insulating material, mounted upon the frame. Theseswitch-springs comprise four main springs f, f', f2, and f3, two uponeach side of the double wedge b. These springs are curved inward attheir free eX- tremities to press upon the block b and are so adjustedas to hold the block normally in its central position, the lever b beingthen nearly horizontal. Then the plunger or button c is presseddownward, the block b' is thrust inward between the springs f and f',forcing these outward. The block comes to rest when the shoulder uponits stem comes against the base-plate a, the curved extremities of thesprings f and f then resting in a stable position in shallow recesses ordepressions b72 in opposite sides of the block b, whereby the lever isretained in this position. lf now the button d be depressed, it willdescend far enough to return the block b to its normal central positionbetween the springs. By the depression of the button e, however, theblock b may be thrust still farther over until it enters between thesprings f2 f3, forcing these apart. The block b is, however, shaped witha regular incline upon the face which enters between the springs f2 f3,so that upon the release of the button e it is returned to its normalcentral position by the pressure of the springs f2 f3. The extremitiesof the springs f, f', f2, and f3 are so adjusted in their position withrelation to the curved faces of the block b that the pressure of eitherpair of springs upon the rounded edge of the wedge b assists to forcethe wedge between the opposite pair of springs, so that the wedge may bemore easily moved.

The springs f, f', f2, and f3 constitute the switch springs or levers ofthe key, and are provided with suitable contact-anvils to alter thecircuit connections as desired. In the form shown the springs f and fare provided with contact-anvils f4 f5, carried at the extremities offiat springs, against which they are thrust when moved outward, andother anvils ff?, against which they close and come to rest in thenormal position of the double wedge or block b', as shown. The springs fG f7 are held in position and prevented from closing together by a blockg of insulating material. On the other side of the key the springsf12and f 3 are provided with similaranvils f8 and f, against which theyclose when thrust outward, and anvils f 10 f 11, upon which they maycome to rest. rlhe spring f2 carries a light spring or rider fl2fastened to it, provided with a contact-point projecting through anaperture in the spring f2 and adjusted to close upon an additional anvilf13 when the wedge b stands in its central position. The spring f3 is,however, in that position of the wedge held out of contact with eitherof its anvils fi or fu.

The dilferent springs are set on edge in saw-cuts in the blocks b3 b3,which may be ot' rubber, and are held in place by cap-blocks b4, screweddown upon them by means of screws b5, passing through the blocks b3 Z13and entering the base-plate ct. The springs of the key are provided withthe usual perforated extensions beyond their supportingblocks, by meansof which circuit-wires may be soldered to them.

The different positions of the key are as follows: The wedge b standsnormally in its middle position, the switch-spring f is closed upon itsanvil f6, and the spring f upon its anvil f7. The spring f2 stands freefrom its anvil flo, but the rider f12 upon it is closed upon its anvilfm. The spring f3 is free from contact with anything. When the button cis depressed, the key assumes a stable position, the extremities of thesprings ff resting in the depressions b2. The springs f and f are thenseparated from their respective anvils f6 f7 and closed against theiranvils f4 and f5. The springs f2 f3 are permitted to approach eachother, the contact-point of the spring f2 resting upon its anvil flo andthe spring f3 upon its anvil f 11. lVhen, however, the button e isdepressed, the springs f and j" are permitted to close upon theiranvils]CG and f7, respectively, the spring f2 is closed against itsanvil f8, the rider j"12 is separated from its anvil fla, and the springf5 is closed upon its anvil fi.

The key is mounted as usual upon the under side of a keyboard h, whichkeyboard is hinged at h to the frame of the switchboard,

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which carries also the apron or shieldhz, upon which the keyboard hcloses. Vhen the keyboard h is turned up into a vertical position, allthe springs and contact-points of the key are exposed for inspection oradjustment, together with the wire connections to them.

In Fig. 4, which represents the circuit to which this particular form ofkey is specially adapted, a pair of connecting-plugs t' z" are showninserted into spring-jacks la k', respectively,supposed to be connectedwith subscriberslines, as in the act of making connection between lines.Generally the like parts 'of the plugs, that is, the tips and sleeves,re-

spectively,are connected together, the sleeves being permanently unitedby a conductor l, and the tips by means of a conductor including varyingportions of the circuit. The usual telephonie and signaling appliancesare shown connected with the conductors uniting the plugs, the key Zbeing employed to alter the circuit connections as desired. ATheseappliances comprise a telephone m, which may be connected to orwithdrawn from connection with the plugs, a clearing-out annunciator nof the self-restoring type, which isalternated with the telephone in itsconnection with the plug-circuits, and a generator o of signalingcurrentfor sending call-signals.

An auxiliary key p is connected in circuit with the telephone, by whichsignaling-currents may be sent out through the answeringplug, or thatwhich is employed to connect with a calling line. The tip of plugz'isunited by a conductor 2 with the spring f, and the tip of plug t" by aconductor 3 with the spring f2. The spring f and the contact-anvil f8are united by conductors 4 and 5, respectively, with the conductor 1joining the sleeves of the plugs. The spring f3 is grounded. Oneterminal of the main or operating magnet n/ of the clearing-outannunciator 'n is connected directly with the conductor 2, while theother extends to the contact-anvil f7. The restoring-magnet n2 isgrounded at one terminal through a battery q and is connected at itsother terminal with the contact-anvil fu. The anvils f6 and ff" areunited directly by a conductor 6, while the anvils f4 and fw areconnected together by a conductor 7, including a condenser r and thecontact-spring p and anvil p2 of the key p. The telephone m is includedin a conductor 8, extending from the anvil f5 to the anvil f1", andincluding the spring psand anvil p4 of key p. The telephone m isgrounded at the center of its coil in the usual manner for testingpurposes. The contact-anvil fi constitutes one terminal of the generatoro, whose other terminal is grounded. The anvils 195196 of the key p areconnected with the terminals of the same generator 0.

To illustrate the employment of this plugcircuit with its combinedapparatus, suppose a call to have been made to connect the line ofspring-jack 7c with the lineof spring-jack lo. The operator, seeing theindividual calllplug i.

ing-annunciator operated, inserts plug t' into spring-jack 7c. Theline-circuit is thus continued through the tip of the plug to conductor2 and through the sleeve to conductor l, and thence,the key l beingalready in position to connect the telephone m with the circuit, thetelephonic current of the subscriber finds a path from conductor 2through the spring f to anvil f4, thence through the conductors 7 and 8,including the telephone fm, to the anvil f5, thence through conductor 4to conductor l. The operator is thus enabled to receive the oral orderof the calling subscriber for the connection desired. She thereupontests the spring-jack la by means of plug t" to determine whether thecorresponding line is already in use or not, the testing-current findingcircuit through conductor 8 .to spring f2, thence to anvil flo, andthence through the telephone m to earth in the usual manner. Havingfound the line tested not in use, she inserts the plug if into thespring-jack 7i," and vdepresses the button e, throwing the wedge b' toits farthest position between thesprings f2 f3. The generator o is nowprovided with a circuit from earth through the anvil f8 to spring f2,and thence, this spring being momentarily insulated from the remainderof the plug-circuit, over the conductor 3 to the tip of the plug, andthence out to line. At the same moment theV grounded spring f3 is closedagainst the anvil fs, grounding the conductor l and providing areturn-circuit over the corresponding side of the line in case thelatter should be a metallic circuit free froln grounds or earthconnections throughout. Upon the release of button c the wedge breturnsto its normal intermediate position between the springs, permitting thesprings f f to separate from the telephone-terminals and to close upontheir anvils f6 f7. The plugcircuit is now complete from the tip of plugi through conductor 2, to spring f, thence to anvil f6, thence throughconductor 6 to anvil f, thence to the rider fw, and to the tip of Theclearing-out annunciator is also connected with the plug-circuit bymeans of the anvil f7, spring f' and conductor 4 being bridged betweenthe sides of the plug-circuit. If the operator should desire to send acallsignal to the substation of the calling line 7s, she would connecther telephone with the plug-circuit by depressing the button d and wouldthen depress the plunger of the key By this means the springs p p3 areclosed to the anvils p5 p6, which constitute terminals of the generator0, whereby signaling-cu rrent is transmitted over a portion of theconductor 7 and the conductor 2 to the tip of the plug fi, and over theconduct-ors 8 and 4 to the sleeve thereof. At the same time theremainder of the plug-circuit extending to the plug t" and connectedwith the telephone m and condenser o" is disconnected, so as not toreceive any of the signaling-current.

It is obvious that our improved key is ca- ICO IIO

pable of many modifications in detail to adapt it to diiierent circuits,and to effect other and different permutations; but

Te claim as new and desire to secure by Letters Patent l. Thecombination with a centrally-pivoted rocking lever, of a button pressingupon each end thereof, and a wedge or block b carried by the leveradapted to move between switch-springs to alter their contacts withanvils provided for them, substantially as described.

2. The combination with a centrally-pivoted rocking lever, of a buttonadapted to act upon each end thereof, a double Wedge Z9 carried by thelever, symmetrically-placed switch-springs upon opposite sides of thedouble wedge, each face of the wedge being' adapted to enter between onepair of switchsprings, and contact-anvils and circuit connections forthe switch-springs, substantially as described.

3. The combination in a listening and ringing key, of an oscillating orrocking lever, a button acting upon one end of the lever to move it inone direction, two buttons adapted to act upon its other extremity tomove it to different distances in the opposite direction,switch-contacts adapted to be operated by the movement of the lever ineither direction, and other switch-contacts operated by its movementthrough different ranges, substantially as described.

4. The combination with an oscillating or rocking lever, of a buttonacting upon one end to move the lever in one direction, and two buttonsacting upon its other extremity to move it to different extents in theopposite direction, the switch-block or double wedge b carried by thelever, symmetrically-disposed switch-springs upon opposite sides of thedouble wedge adapted to be moved thereby, and different sets ofcontact-points whose connections with their respective springs arealtered in accordance with the movement of the lever in dierentdirections and to dierent extents, substantially as described.

5. The combination with a hinged keyboard or shelf, of keys mountedthereon having their switch-springs placed on edge and arranged in aplane parallel with the keyboard, whereby the keys may be readilyinspected, as described.

6. In combination, the oscillating lever b carrying the double wedge1J', the keys c and d acting upon the lever on opposite sides of itsfulcrum, the switch-springs f f' f2 and f3 arranged symmetrically inpairs on opposite sides of the double wedge b, and switch contacts oranvils for the springs, as described.

7 The combination with the oscillating lever b carrying the wedge b', ofthe buttons c cl and e acting upon the lever, the switchsprings f f f2and f3 arranged symmetrically in pairs upon opposite sides of the wedgeb',

the parts being so adjusted that pressure upon button c forces the wedgebetween the springs f f and pressure upon button c forces it betweensprings f2 f3, while pressure upon button d returns it to its normalcentral position, as described.

8. The combination with the listening and ringing key, of the groundedswitch-spring f8 oscillating between contact-anvils f9 f to ground theplu g-circuit in ringing, or to close the local circuit of therestoring-coil of the clearing-out annunciator when the telephone isconnected with the plug-circuit, as described.

9. In combination, two connecting-plugs, a combination listening andringing key having its switch-springs connected with the diierentcontact-pieces of the connecting-plugs, the key being provided with anoscillating lever and with buttons pressing upon opposite ends of thelever, said lever being adapted to move the switch-springs to connectthetelephone with the plug-circuit when in one position, and to disconnectthe same when in another position, as described.

10. ln combination, a plug-circuit, a key included therein, said keybeing provided with an oscillating lever acted upon by three buttons,said lever controlling switch-contacts to connect a telephone with theplug-circuit when one key is depressed, to disconnect said telephonewhen another button is depressed, and to both disconnect the telephoneand close the circuit of a local generator of signaling-current to thecircuit when a third button is depressed, substantially as described.

1l. rlhe combination with a two-part plug adapted for use with metalliccircuits, a plugcircuit and a key connected therewith, said key beingadapted when operated to disconnect one contact-piece of the plug fromthc remainder of the plug-circuit and to connect it with one terminal ofa grounded generator, and to ground the other side of the plug-circuit,as described.

12. In combination, a lever and means for moving it about its pivot, adouble wedge carried on the lever, two sets of switch-springs and theircontact-points on opposite sides oi' the wedge in a plane substantiallythat in which the wedge is adapted to move, said wedge being adapted tolie between the presented extremities of all the switch-springs in anormal position, meansA for applying spring-pressure to the lever toreturn it to said normal position from between one pair ofswitch-springs, the wedge being adapted to remain fixed when thrustbetween said other switch -springs, substantially as described.

13. The combination with two pairs of symmetrically-disposedswitch-springs, of a double wedge between the presented ends of thesprings, mounted upon a rocking lever, a press-button acting upon eachend of the lever, the range of movement of the lever and ICO IIO

564,456 i I s:

the press-hittons being so adjusted that one d button may move the Wedgefrom its normal intermediate position to a position between one pair ofsprings, and the other butt-on may move the Wedge from this position toits normal position and thence between the other pair of springs,substantially as described.

In Witness whereof We hereunto subscribe our names this 19th day ofJuly, A. D. 1893.

CHARLES E. SCRIBNER. FRANK R. MCBERTY.

Witnesses:

CHARLES A. BROWN, GEORGE L. CRAGG.

